The invention discloses a corrosion-resistant magnesium aluminum alloy chromium-free passivation solution, which comprises the following components: 10-40 parts of water-base resin, 1-10 parts of nanoparticle sol, 1-10 parts of fluoric-containing acid, 1-5 parts of fluoric acid-containing salt, 1-5 parts of a rare earth catalyst, 1-10 parts of a silane coupling agent, 1-5 parts of a corrosion inhibitor, 1-2 parts of a complexing agent and 40-70% of water. The corrosion-resistant magnesium aluminum alloy chromium-free passivation solution does not contain chromium and other toxic and harmful substances, meets the ROHS environmental protection law of the European Union, and meanwhile, can form an organic and inorganic composite passivation film and a thin film on the surface of a magnesium aluminum layer, and the formed composite passivation film has an excellent physical property and corrosion resistance, and has higher corrosion resistance and long salt fog time, so that the corrosion resistance of a magnesium aluminum alloy plate is better improved.